board_status/to-wiki: Update bucketize script

- Fix TODO: restrict $1 to allowed values.
- Specifically exclude 'oem' board status directories.
- Exclude any directory that doesn't follow the date format to keep
the script from breaking again in the future if something it doesn't
recognize is pushed.  Just ignore it for the wiki.
- Fix shellcheck warnings.

Change-Id: I2864f09f5f1b1f5ec626d06e4849830400ef5814
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/18225
Tested-by: build bot (Jenkins)
Reviewed-by: Timothy Pearson <tpearson@raptorengineering.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

util/board_status/to-wiki/bucketize.sh

@@ -4,30 +4,42 @@
 #   into buckets of the given granularity
 
 weekly() {
-	date --date="$1" +%GW%V
+	date --date="$1" +%GW%V 2>/dev/null
+	return $?
 }
 
 monthly() {
-	date --date="$1" +%Y-%m
+	date --date="$1" +%Y-%m 2>/dev/null
+	return $?
 }
 
 quarterly() {
-	date --date="$1" "+%Y %m"  | awk '{ q=int(($2-1)/3+1); print $1 "Q" q}'
+	date --date="$1" "+%Y %m"  2>/dev/null | awk '{ q=int(($2-1)/3+1); print $1 "Q" q}'
+	return $?
 }
 
-# TODO: restrict $1 to allowed values
+# Restrict $1 to allowed values
+if [ "$1" != "weekly" ] && [ "$1" != "monthly" ] && [ "$1" != "quarterly" ]; then
+	exit 1
+fi
 
 curr=""
 sort -r -k4 -t/ | while read file; do
-	timestamp=`printf $file | cut -d/ -f4 | tr _ :`
-	new=`$1 $timestamp`
+	# Exclude 'oem' directories
+	if echo "$file" | grep -q '/oem/'; then continue; fi
+	timestamp=$(printf "%s" "$file" | cut -d/ -f4 | tr _ :)
+
+	# If the directory is not a date, skip it.
+	new=$($1 "$timestamp");retval=$?
+	if [ "$retval" != "0" ]; then continue; fi
+
 	if [ "$new" != "$curr" ]; then
 		if [ "$curr" != "" ]; then
 			printf "\n"
 		fi
-		printf "$new:"
+		printf "%s:" "$new"
 		curr=$new
 	fi
-	printf "$file "
+	printf "%s " "$file"
 done
 printf "\n"